解决Linux操作系统下AES解密失败的问题

你的名字 2022-05-14 02:42 241阅读 0赞

**现象描述：**

windows上加解密正常，linux上加密正常，解密时发生 如下异常：

javax.crypto.BadPaddingException: Given final block not properly padded

at com.sun.crypto.provider.SunJCE\_f.b(DashoA13\*..)  
       at com.sun.crypto.provider.SunJCE\_f.b(DashoA13\*..)  
       at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13\*..)  
       at javax.crypto.Cipher.doFinal(DashoA13\*..)  
       at chb.test.crypto.AESUtils.crypt(AESUtils.java:386)  
       at chb.test.crypto.AESUtils.AesDecrypt(AESUtils.java:254)  
       at chb.test.crypto.AESUtils.main(AESUtils.java:40)

**解决方法：**

经过检查之后，定位在生成KEY的方法上，如下：

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1.  **public** **static** SecretKey getKey (String strKey) \{  
2.           **try** \{           
3.              KeyGenerator \_generator = KeyGenerator.getInstance( "AES" );  
4.              \_generator.init(128, **new** SecureRandom(strKey.getBytes()));  
5.                  **return** \_generator.generateKey();  
6.          \}  **catch** (Exception e) \{  
7.               **throw** **new** RuntimeException( " 初始化密钥出现异常 " );  
8.          \}  
9.        \}

修改到如下方式，问题解决：

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1.  **public** **static** SecretKey getKey(String strKey) \{  
2.         **try** \{           
3.            KeyGenerator \_generator = KeyGenerator.getInstance( "AES" );  
4.             SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );  
5.            secureRandom.setSeed(strKey.getBytes());  
6.            \_generator.init(128,secureRandom);  
7.                **return** \_generator.generateKey();  
8.        \}  **catch** (Exception e) \{  
9.             **throw** **new** RuntimeException( " 初始化密钥出现异常 " );  
10.       \}  
11.     \}

**原因分析**

SecureRandom 实现完全隨操作系统本身的內部狀態，除非調用方在調用 getInstance 方法之後又調用了 setSeed 方法；该实现在 windows 上每次生成的 key 都相同，但是在 solaris 或部分 linux 系统上则不同。

原因二：

1、加密完byte\[\] 后，需要将加密了的byte\[\] 转换成base64保存，如：   
BASE64Encoder base64encoder = new BASE64Encoder();   
String encode=base64encoder.encode(bytes)；   
  
2、解密前，需要将加密后的字符串从base64转回来再解密，如：   
BASE64Decoder base64decoder = new BASE64Decoder();   
byte\[\] encodeByte = base64decoder.decodeBuffer(str);

完整例子：

Java代码  ![收藏代码][icon_star.png]

import java.io.IOException;  
import java.io.UnsupportedEncodingException;  
import java.security.InvalidKeyException;  
import java.security.NoSuchAlgorithmException;  
import java.security.SecureRandom;  
  
import javax.crypto.BadPaddingException;  
import javax.crypto.Cipher;  
import javax.crypto.IllegalBlockSizeException;  
import javax.crypto.KeyGenerator;  
import javax.crypto.NoSuchPaddingException;  
import javax.crypto.SecretKey;  
import javax.crypto.spec.SecretKeySpec;  
  
import sun.misc.BASE64Decoder;  
import sun.misc.BASE64Encoder;  
   
public class SecurityAES \{    
    private final static String encoding = "UTF-8";     
    /\*\*  
     \* AES加密  
     \*    
     \* @param content  
     \* @param password  
     \* @return  
     \*/    
    public static String encryptAES(String content, String password) \{    
        byte\[\] encryptResult = encrypt(content, password);    
        String encryptResultStr = parseByte2HexStr(encryptResult);    
        // BASE64位加密    
        encryptResultStr = ebotongEncrypto(encryptResultStr);    
        return encryptResultStr;    
    \}    
   
    /\*\*  
     \* AES解密  
     \*    
     \* @param encryptResultStr  
     \* @param password  
     \* @return  
     \*/    
    public static String decrypt(String encryptResultStr, String password) \{    
        // BASE64位解密    
        String decrpt = ebotongDecrypto(encryptResultStr);    
        byte\[\] decryptFrom = parseHexStr2Byte(decrpt);    
        byte\[\] decryptResult = decrypt(decryptFrom, password);    
        return new String(decryptResult);    
    \}    
   
        /\*\*  
     \* 加密字符串  
     \*/    
    public static String ebotongEncrypto(String str) \{    
        BASE64Encoder base64encoder = new BASE64Encoder();    
        String result = str;    
        if (str != null && str.length() > 0) \{    
            try \{    
                byte\[\] encodeByte = str.getBytes(encoding);    
                result = base64encoder.encode(encodeByte);    
            \} catch (Exception e) \{    
                e.printStackTrace();    
            \}    
        \}    
        //base64加密超过一定长度会自动换行 需要去除换行符    
        return result.replaceAll("\\r\\n", "").replaceAll("\\r", "").replaceAll("\\n", "");    
    \}    
   
    /\*\*  
     \* 解密字符串  
     \*/    
    public static String ebotongDecrypto(String str) \{    
        BASE64Decoder base64decoder = new BASE64Decoder();    
        try \{    
            byte\[\] encodeByte = base64decoder.decodeBuffer(str);    
            return new String(encodeByte);    
        \} catch (IOException e) \{    
            e.printStackTrace();    
            return str;    
        \}    
    \}    
    /\*\*     
     \* 加密     
     \*      
     \* @param content 需要加密的内容     
     \* @param password  加密密码     
     \* @return     
     \*/      
    private static byte\[\] encrypt(String content, String password) \{       
            try \{                  
                    KeyGenerator kgen = KeyGenerator.getInstance("AES");     
                    //防止linux下 随机生成key    
                    SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );       
                    secureRandom.setSeed(password.getBytes());       
                    kgen.init(128, secureRandom);    
                    //kgen.init(128, new SecureRandom(password.getBytes()));       
                    SecretKey secretKey = kgen.generateKey();       
                    byte\[\] enCodeFormat = secretKey.getEncoded();       
                    SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");       
                    Cipher cipher = Cipher.getInstance("AES");// 创建密码器       
                    byte\[\] byteContent = content.getBytes("utf-8");       
                    cipher.init(Cipher.ENCRYPT\_MODE, key);// 初始化       
                    byte\[\] result = cipher.doFinal(byteContent);       
                    return result; // 加密       
            \} catch (NoSuchAlgorithmException e) \{       
                    e.printStackTrace();       
            \} catch (NoSuchPaddingException e) \{       
                    e.printStackTrace();       
            \} catch (InvalidKeyException e) \{       
                    e.printStackTrace();       
            \} catch (UnsupportedEncodingException e) \{       
                    e.printStackTrace();       
            \} catch (IllegalBlockSizeException e) \{       
                    e.printStackTrace();       
            \} catch (BadPaddingException e) \{       
                    e.printStackTrace();       
            \}       
            return null;       
    \}      
   
   
    /\*\*解密     
     \* @param content  待解密内容     
     \* @param password 解密密钥     
     \* @return     
     \*/      
    private static byte\[\] decrypt(byte\[\] content, String password) \{       
            try \{       
                     KeyGenerator kgen = KeyGenerator.getInstance("AES");     
                   //防止linux下 随机生成key    
                     SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG" );       
                     secureRandom.setSeed(password.getBytes());       
                     kgen.init(128, secureRandom);    
                     //kgen.init(128, new SecureRandom(password.getBytes()));       
                     SecretKey secretKey = kgen.generateKey();       
                     byte\[\] enCodeFormat = secretKey.getEncoded();       
                     SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");                   
                     Cipher cipher = Cipher.getInstance("AES");// 创建密码器       
                    cipher.init(Cipher.DECRYPT\_MODE, key);// 初始化       
                    byte\[\] result = cipher.doFinal(content);       
                    return result; // 加密       
            \} catch (NoSuchAlgorithmException e) \{       
                    e.printStackTrace();       
            \} catch (NoSuchPaddingException e) \{       
                    e.printStackTrace();       
            \} catch (InvalidKeyException e) \{       
                    e.printStackTrace();       
            \} catch (IllegalBlockSizeException e) \{       
                    e.printStackTrace();       
            \} catch (BadPaddingException e) \{       
                    e.printStackTrace();       
            \}       
            return null;       
    \}      
   
    /\*\*将二进制转换成16进制     
     \* @param buf     
     \* @return     
     \*/      
    public static String parseByte2HexStr(byte buf\[\]) \{       
            StringBuffer sb = new StringBuffer();       
            for (int i = 0; i < buf.length; i++) \{       
                    String hex = Integer.toHexString(buf\[i\] & 0xFF);       
                    if (hex.length() == 1) \{       
                            hex = '0' + hex;       
                    \}       
                    sb.append(hex.toUpperCase());       
            \}       
            return sb.toString();       
    \}      
   
   
    /\*\*将16进制转换为二进制     
     \* @param hexStr     
     \* @return     
     \*/      
    public static byte\[\] parseHexStr2Byte(String hexStr) \{       
            if (hexStr.length() < 1)       
                    return null;       
            byte\[\] result = new byte\[hexStr.length()/2\];       
            for (int i = 0;i< hexStr.length()/2; i++) \{       
                    int high = Integer.parseInt(hexStr.substring(i\*2, i\*2+1), 16);       
                    int low = Integer.parseInt(hexStr.substring(i\*2+1, i\*2+2), 16);       
                    result\[i\] = (byte) (high \* 16 + low);       
            \}       
            return result;       
    \}      
   
\}

[view plain]: http://blog.csdn.net/hbcui1984/archive/2010/07/21/5753083.aspx
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